I dont know if you thought of this, just thought I would bring it up. Some type of liner or coating would probably need to be sprayed or put on the inside of the water tanks for it to be safe to drink without being filtered or boiled first. I know I wouldnt want to drink water from the trucks at my fire department. The trucks are kept full of water so they can roll immediately in case of a fire, I dont know if it is mildew, rust, or what but any water that comes out of those tanks has a reddish-brown color to it. I know this doesnt affect your scenario in any way but just thought it would be useful info.

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